Electrochromic polymer and synthesis and uses thereof

ABSTRACT

The disclosure relates generally to black-to-transmissive electrochromic polymers having superior properties such as absorbance of across the entire visible spectrum and an obvious color change from black to transmissive with an applied voltage. The disclosure also relates to methods for synthesizing or using the same. Further, the disclosure also relates to black-to-transmissive electrochromic polymer thin films comprising the black-to-transmissive electrochromic polymers, as well as electrochromic devices comprising the black-to-transmissive electrochromic polymers or thin films.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 16/033,012, now allowed, filed on Jul. 11, 2018, which is based onand claims priority to U.S. Provisional Application No. 62/532,693,filed Jul. 14, 2017, entitled “Method for synthesizing electrochromicpolymer thin films.” The entire contents of the above-referencedapplication are all incorporated herein by reference.

TECHNICAL FIELD

The disclosure relates generally to electrochromic polymer thin films,and more particularly, to black-to-transmissive electrochromic polymerthin films with a high optical contrast and a fast switch, and methodsof using and making the same.

BACKGROUND

Electrochromism refers to a reversible optical spectrum change upon anelectron transfer reaction induced via an application of voltage.Recently, electrochromic (EC) materials play an increasingly vital rolein both academic and practical areas since it achieves a reversible andhighly stable variation of transmissive/absorptive spectra and tunablecolors between doped and undoped states, and hence possesses a greatpotential to be used in smart windows mirror, sunglasses, digitalsignage and displays, as well as electronic paper.

Among various EC material candidates, inorganic materials such as(transition) metal oxides and their complexes are the most widelyexploited color-changing materials due to broad polaron absorption andhigh photochemistry, nevertheless, always limited by a slow respond timeand low coloration efficiency. A polaron is a quasiparticle used tounderstand interactions between electrons and atoms in a solid material.A photochemistry refers to a chemical reaction caused by absorption oflight. Alternatively, conjugated polymers have been recognized asdesired materials in all sorts of electrochromic devices (ECDs) fortheir tunable colors, high optical contrast, easy processability, andlong-term stability. Currently, many investigations have been devotedinto the various saturated colored-to-transmissive polymeric ECDs fromtheir neutral states to doped states. Especially, black-to-transmissiveelectrochromic polymers (ECPs) is gradually becoming a hot spot as it issignified to be a promising material for privacy glass and smartwindows. However, there still remains a challenge due to complexity andincompleteness of absorption over the whole visible spectrum in theneutral state, followed by bleaching out in a fully oxidized state.

Up to now, significant efforts have been devoted to design and obtain adesired black color and a full spectrum, and various materials andstrategies are emerging. As mentioned, although metal oxides and theircomplex, such as porous NiO, Co-based polymer, CuO₂, IrO₂ have beenextensively investigated and can be served as the black-to-transmissiveelectrochrotnes, they show inferior EC performances (low colorationefficiency and slow color change) compared with organic polymermaterials.

Organic black-to-transmissive EC materials include (1) individualcopolymers absorbing the entire visible spectrum, and (2) complementarycompositions based on “color-mixing” theory to achieve a completespectrum and a black-to-transmissive EC display. When two or moredifferent monomers unite together to polymerize, their result is calleda copolymer and its process is called copolymerization. Various sorts ofblack-to-transmissive ECDs are reported with the second method byblending multicolored compounds or constructing complementarymultilayers. Consequently cathodically coloring layer EC materials canpotentially complement an anodically coloring electrode to form apanchromatic absorption spectrum within the visible spectrum. However,the resulting colors obtained by this method show a relatively lowoptical contrast, complex process, or pseudo-color phenomenon. Also,performance and manipulation limitations seriously limit theapplications in a narrow range.

Initiated by others works on the design and synthesis of conjugated ECPswith neutral state colors of blue, green or black, band gaps of thesematerials must be lower than 1.75 eV. To construct a low-band gapsystem, a “donor-acceptor” (D-A) strategy via alternatingelectron-donating and electron-accepting (i.e., electron-rich andelectron-deficienr) units, is verified as an effective solution and hasbeen widely employed to synthesize individual copolymers. Nevertheless,the band gap is not the only factor in determination of a color state. Acolor state is a comprehensive result of wavelengths and intensitieswith different optical transitions. More importantly, there are multipleabsorption spectra with various breadths existing in the D-A copolymersstructure. The first neutral-state black-to-transmissive polymericelectrochrome was proposed and developed by Reynolds group (P. M.Beaujuge, S. Ellinger, J. R. Reynolds, the donor-acceptor approachallows a black-to-transmissive switching polymeric electrochrome, Nat.Mater. 2008, 7, 795-799). Then they made further improvements andinvestigated several kinds of copolymers in lower fabrication andprocessing costs, as well as good performance, exhibiting fast switchingresponds, high optical contrast. Nevertheless, additional improvementsare still required for more uniform and broad absorbance across theentire visible spectrum to meet needs of the applications.

SUMMARY

This disclosure presents individual black-to-transmissive electrochromiccopolymers which absorb over the entire visible spectrum, and methods ofpreparing the copolymers as well as their uses in ECDs.

One aspect of the present disclosure is directed to ablack-to-transmissive electrochromic polymer having more uniform andbroad absorbance across the entire visible spectrum. In someembodiments, the black-to-transmissive electrochromic polymer is ofFormula (I):

-   -   wherein    -   is of the formula

-   -   of the formula

-   -    or a combination thereof;    -   of the formula

-   -   each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ is        independently hydrogen, optionally substituted C₁-C₃₀ alkyl,        optionally substituted C₂-C₃₀ alkenyl, optionally substituted        C₂-C₃₀ alkynyl, optionally substituted C₂-C₃₀ alkylcarbonyl,        optionally substituted C₁-C₃₀ alkoxy, optionally substituted        C₃-C₃₀ alkoxyalkyl, optionally substituted C₂-C₃₀        alkoxycarbonyl, optionally substituted C₄-C₃₀        alkoxycarbonylalkyl, optionally substituted C₁-C₃₀        aminylcarbonyl, optionally substituted C₄-C₃₀ aminylalkyl,        optionally substituted C₁-C₃₀ alkylaminyl, optionally        substituted C₁-C₃₀ alkyl sulfonyl, optionally substituted C₃-C₃₀        alkylsulfonylalkyl, optionally substituted C₆-C₁₈ aryl,        optionally substituted C₃-C₁₅ cycloalkyl, optionally substituted        C₃-C₃₀ cycloalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkyl, optionally substituted C₅-C₃₀        cycloalkylalkyloxy, optionally substituted C₁-C₁₂ heterocyclyl,        optionally substituted C₁-C₁₂ heterocyclyloxy, optionally        substituted C₃-C₃₀ heterocyclylalkyloxy, optionally substituted        C₁-C₃₀ heterocyclylalkyloxy, optionally substituted C₁-C₃₀        heterocyclylaminyl, optionally substituted C₅-C₃₀        heterocyclylalkylaminyl, optionally substituted C₂-C₁₂        heterocyclylcarbonyl, optionally substituted C₃-C₃₀        heterocyclylalkyl, optionally substituted C₁-C₁₃ heteroaryl, or        optionally substituted C₃-C₃₀ heteroarylalkyl;    -   each r, s and t is independently an integer of equal to or        greater than 1;    -   n is an integer of equal to or greater than 1;    -   represents connection to the rest of the molecule; and    -   the average ratio of        ,        , and        in the polymer is x:y:z, wherein x ranges from about 0.2 to        about 0.6, y ranges from about 1.2 to about 1.45, and z ranges        from about 0.2 to about 0.45, and x+y+z=2.

Another aspect of the present disclosure is directed to ablack-to-transmissive electrochromic polymer. The synthesized blackpolymer may absorb across the entire visible spectrum and realize anobvious color change from black (e.g., L*=49.2, a*=−10-5, b*=−10˜5, suchas a*=3.6, b*=−7.7) to transmissive (e.g., L*=85, a*=−10-5, b*=−10-5,such as a*=−4.6, b*=−5.8) with an applied voltage of 0-1.2 V. An opticalcontrast as high as nearly 70% may be achieved within 10 seconds inelectrochromic thin films made of the black polymer.

Another aspect of the present disclosure is directed to a method forsynthesizing a black-to-transmissive electrochromic polymer viacontrolling monomer feed ratios in a direct arylation polymerization. Insome embodiments, to synthesize the black polymer, with 1.0 equivalentof monomer 1, the feed ratios of monomers 2, 3 and 4 may range from0.2-0.6, 0.2-0.45, 0.2-0.35, respectively, wherein monomers 1, 2, 3 and4 are as described herein.

Another aspect of the present disclosure is directed to electrochromicthin films made of the black polymer, and a black-to-transmissive ECDbased on the as-prepared electrochromic films may be designed using atransparent indium tin oxide (ITO) as a counter electrode for chargestorage. The ECD may display high contrasts for 43.6%, switching from asaturated black state (L*=37.8, a*=−5˜0, b*=−10˜0, such as a*=2.5,b*=−6.4) to a transmissive state (L*=72.6, a*=−5˜0, b*=−5˜0, such asa*=−8.0, b*=−6.5).

It is to be understood that the foregoing general description and thefollowing detailed description are exemplary and explanatory only, andare not restrictive of the disclosure, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which constitute a part of this disclosure,illustrate several non-limiting embodiments and, together with thedescription, serve to explain the disclosed principles.

FIG. 1 is a graphical diagram illustrating a reaction scheme for asynthesis of black polymers, consistent with exemplary embodiments ofthe present disclosure.

FIG. 2A is a graph illustrating measurement results of solutionabsorption of black polymers in chloroform; FIG. 2B is a graphillustrating measurement results of normalized film absorption of theblack polymers, consistent with exemplary embodiments of the presentdisclosure.

FIG. 3A is a graph illustrating measurement results of cyclicvoltammograms of polymer P4; FIG. 3B is a graph illustrating measurementresults of spectroelectrochemistry of polymer P4, FIG. 3C a graphillustrating lightness (L*) as a function of applied potential forspin-coated P4 film, and FIG. 3D is a graph illustrating a summary ofthe square wave potential step chronoabsorptometry of a P4 spin-coatedITO; consistent with exemplary embodiments of the present disclosure.

FIGS. 4A-D are graphs illustrating square-wave potential-stepchronoabsorptometry of P1, P2, P3 and P4 spin-coated ITOs respectively,consistent with exemplary embodiments of the present disclosure.

FIGS. 5A-B are graphs illustrating A transmittance and B current changeof polymer P4 in 10 s interval steps between 0 and 1.2 V, consistentwith exemplary embodiments of the present disclosure.

FIG. 6 is a graph illustrating measurement results of transmittancespectra of an ECD, consistent with exemplary embodiments of the presentdisclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. The followingdescription refers to the accompanying drawings in which the samenumbers in different drawings represent the same or similar elementsunless otherwise represented. The implementations set forth in thefollowing description of exemplary embodiments consistent with thepresent disclosure do not represent all implementations consistent withthe disclosure. Instead, they are merely examples of systems and methodsconsistent with aspects related to the disclosure.

As used herein, the term “comprising” is intended to mean that thecompositions and methods include the recited elements, but not excludingothers. “Consisting essentially of” when used to define compositions andmethods, shall mean excluding other elements of any essentialsignificance to the combination. For example, a composition consistingessentially of the elements as defined herein would not exclude otherelements that do not materially affect the basic and novelcharacteristic(s) of the claimed invention.” Consisting of shall meanexcluding more than trace amount of other ingredients and substantialmethod steps recited. Embodiments defined by each of these transitionterms are within the scope of this invention.

Numeric ranges are also inclusive of the numbers defining the range.Additionally, the singular forms “a”, “an” and “the” include pluralreferents unless the context clearly dictates otherwise.

Reference throughout this specification to “one embodiment,” “anembodiment” or “some embodiments” means that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present invention. Thus,the appearances of the phrases “in one embodiment,” “in an embodiment”or “in some embodiments” in various places throughout this specificationare not necessarily all referring to the same embodiment or embodiments,but may be in some instances. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

The term “about” when used before a numerical value indicates that thevalue may vary within reasonable range, such as ±10%, ±5%, and ±1%.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of skill in theart to which this invention belongs. For instance, “amino” refers to the—NH₂ radical; “hydroxy” or “hydroxyl” refers to the OH radical; “thioxo”refers to the ═S substituent, etc.

Alkyl” refers to a straight or branched hydrocarbon chain radicalconsisting solely of carbon (C) and hydrogen (H) atoms, which issaturated or unsaturated (i.e., contains one or more double and/ortriple bonds), having from 1 to 30 carbon atoms (C₁-C₃₀ alkyl), andwhich is attached to the rest of the molecule by a single bond, e.g.,methyl, ethyl, n-propyl, 1-methylethyl (iso-propyl), n-butyl, n-pentyl,1,1-dimethylethyl (t-butyl), 3-methylhexyl, 2-methylhexyl, ethenyl,prop-1-enyl, but-1-enyl, pent-1-enyl, penta-1,4-dienyl, ethynyl,propynyl, butynyl, pentynyl, hexynyl, and the like. Unless statedotherwise specifically in the specification, an alkyl group may beoptionally substituted.

“Alkylene” or “alkylene chain” refers to a straight or branched divalenthydrocarbon chain linking the rest of the molecule to a radical group,consisting solely of carbon and hydrogen, which is saturated orunsaturated (i.e., contains one or more double and/or triple bonds), andhaving from 2 to 30 carbon atoms (C₂-C₃₀ alkylene), e.g., methylene,ethylene, propylene, n-butylene, ethenylene, propenylene, n-butenylene,propynylene, n-butynylene, and the like. The alkylene chain is attachedto the rest of the molecule through a single or double bond and to theradical group through a single or double bond. The points of attachmentof the alkylene chain to the rest of the molecule and to the radicalgroup can be through one carbon or any two carbons within the chain.Unless stated otherwise specifically in the specification, an alkylenechain may be optionally substituted.

“Alkylcarbonyl” refers to a radical of the formula —(C═O)R^(a) whereR^(a) is a C₁-C₃₀ alkyl radical as defined above. Unless statedotherwise specifically in the specification, an alkylcarbonyl group maybe optionally substituted.

“Alkoxy” refers to a radical of the formula —OR′ where R^(a) is a C₁-C₃₀alkyl radical as defined above. A “haloalkoxy” is an alkoxy group asdefined above, wherein at least one carbon-hydrogen bond is replacedwith a carbon-halogen bond. Unless stated otherwise specifically in thespecification, an alkoxy or haloalkoxy group may be optionallysubstituted.

“Alkoxyalkyl” refers to a radical of the formula —R^(b)OR^(a) whereR^(a) is a C₁-C₃₀ alkyl radical as defined above, and R^(b) is a C₂-C₃₀alkylene radical as defined above. A “haloalkoxyalkyl” group is analkoxyalkyl, wherein at least one carbon-hydrogen bond is replaced witha carbon-halogen bond. Unless stated otherwise specifically in thespecification, an alkoxyalkyl or haloalkoxyalkyl group may be optionallysubstituted.

“Alkoxycarbonyl” refers to a radical of the formula —(C═O)OR^(a) whereR^(a) is a C₁-C₃₀ alkyl radical as defined above. Unless statedotherwise specifically in the specification, an alkoxycarbonyl group maybe optionally substituted.

“Alkoxycarbonylalkyl” refers to a radical of the formula—R^(b)(C═O)OR^(a) where R^(a) is a C₁-C₃₀ alkyl radical as definedabove, and R^(b) is a C₂-C₃₀ alkylene as defined above. Unless statedotherwise specifically in the specification, an alkoxycarbonylalkylgroup may be optionally substituted.

“Aminylcarbonyl” refers to a radical of the formula —(C═O)N(R^(a))₂,where each R^(a) is independently H or a C₁-C₃₀ alkyl group as definedabove. Unless stated otherwise specifically in the specification, anaminylcarbonyl group may be optionally substituted.

“Aminylalkyl” refers to a radical of the formula —R^(a)N(R^(b))₂ whereR^(a) is a C₂-C₃₀ alkylene as defined above, and each R^(b) isindependently a C₁-C₃₀ alkyl radical as defined above. Unless statedotherwise specifically in the specification, an aminylalky group may beoptionally substituted.

“Alkylaminyl” refers to a radical of the formula —NHR^(a) or—NR^(a)R^(a) where each R^(a) is independently a C₁-C₃₀ alkyl radical asdefined above, and R^(a) is a C₁-C₃₀ alky radical as defined above.Unless stated otherwise specifically in the specification, an aminylalkygroup may be optionally substituted.

“Alkylsulfonyl” refers to a radical of the formula —S(O)₂R^(a) whereR^(a) is a C₁-C₃₀ alkyl radical as defined above. Unless statedotherwise specifically in the specification, an alkylsulfonyl group maybe optionally substituted.

“Alkylsulfonylalkyl” refers to a radical of the formula —R^(b)S(O)₂R^(a)where R^(a) is a C₁-C₃₀ alkyl radical as defined above, and R^(b) is aC₂-C₃₀ alkylene radical as defined above. Unless stated otherwisespecifically in the specification, an alkylsulfonylalkyl group may beoptionally substituted.

“Cyanoalkyl” is a C₁-C₃₀ alkyl group as defined above, wherein at leastone carbon-hydrogen bond is replaced with a carbon-cyano bond. Unlessstated otherwise specifically in the specification, a cyanoalkyl groupmay be optionally substituted.

“Hydroxylalkyl” refers to a C₁-C₃₀ alkyl radical as defined above, whichhas been substituted by one or more hydroxyl groups. Unless statedotherwise specifically in the specification, a hydroxylalkyl group maybe optionally substituted.

“Aryl” refers to a hydrocarbon ring system radical comprising hydrogen,6 to 18 carbon atoms and at least one aromatic ring. For purposes ofthis invention, the aryl radical may be a monocyclic, bicyclic,tricyclic or tetracyclic ring system, which may include fused or bridgedring systems. Aryl radicals include, but are not limited to, arylradicals derived from phenyl, naphthyl, anthryl, etc. Unless statedotherwise specifically in the specification, the term “aryl” is meant toinclude aryl radicals that are optionally substituted.

“Conjugated polymer” refers to a polymer having alternating single anddouble (or triple) carbon-carbon bonds along at least a portion of thepolymer backbone.

“Cycloalkyl” or “carbocyclic ring” refers to a stable non-aromaticmonocyclic or polycyclic hydrocarbon radical consisting solely of carbonand hydrogen atoms, which may include fused or bridged ring systems,having from 3 to 15 carbon atoms, and which is saturated or unsaturatedand attached to the rest of the molecule by a single bond. Monocyclicradicals may include, but are not limited to, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Polycyclicradicals may include, but are not limited to, adamantyl, norbornyl,decalinyl, 7,7-dimethyl-bicyclo[2.2.1]heptanyl, and the like. Unlessotherwise stated specifically in the specification, a cycloalkyl groupmay be optionally substituted.

“Cycloalkylaminyl” refers to a radical of the formula —NR^(a)R^(c) whereR^(a) is, independently, H or a C₁-C₃₀ alkyl radical as defined above,and R^(c) is a C₃-C₁₅ cycloalkyl radical as defined above. Unless statedotherwise specifically in the specification, an aminylalky group may beoptionally substituted.

“Cycloalkylalkylaminyl” refers to a radical of the formula—NR^(a)R^(b)—R^(c) where R^(a) is independently H or a C₁-C₃₀ alkylradical as defined above, R^(b) is a C₂-C₃₀ alkylene radical as definedabove, and R^(c) is a C₃-C₁₅ cycloalkyl radical as defined above. Unlessstated otherwise specifically in the specification, acycloalkylalkylaminyl group may be optionally substituted.

“Cycloalkylalkyl” refers to a radical of the formula —R^(b)R^(c) whereR^(b) is a C₂-C₃₀ alkylene chain as defined above, and R^(c) is a C₃-C₁₅cycloalkyl radical as defined above. Unless stated otherwisespecifically in the specification, a cycloalkylalkyl group may beoptionally substituted.

“Cycloalkylalkyloxy” refers to a radical of the formula —OR^(b)R^(c)where R^(b) is a C₂-C₃₀ alkylene chain as defined above, and R^(c) is aC₃-C₁₅ cycloalkyl radical as defined above. Unless stated otherwisespecifically in the specification, a cycloalkylalkyloxy group may beoptionally substituted.

“Fused” refers to any ring structure described herein which is fused toan existing ring structure in the compounds of the invention. When thefused ring is a heterocyclyl ring or a heteroaryl ring, any carbon atomon the existing ring structure which becomes part of the fusedheterocyclyl ring or the fused heteroaryl ring may be replaced with anitrogen atom.

“Halo” or “halogen” refers to bromo, chloro, fluoro or iodo.

“Haloalkyl” refers to a C₁-C₃₀ alkyl radical as defined above, that issubstituted by one or more halo radicals as defined above, e.g.,trifluoromethyl, difluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl,1,2-difluoroethyl, 3-bromo-2-fluoropropyl, 1,2-dibromoethyl, and thelike. Unless stated otherwise specifically in the specification, ahaloalkyl group may be optionally substituted.

“Heterocyclyl” or “heterocyclic ring” refers to a stable 3- to18-membered non-aromatic ring radical which consists of 2 to 12 carbonatoms and from 1 to 6 heteroatoms selected from the group consisting ofnitrogen, oxygen and sulfur. Unless stated otherwise specifically in thespecification, the heterocyclyl radical may be a monocyclic, bicyclic,tricyclic or tetracyclic ring system, which may include fused or bridgedring systems; and the nitrogen, carbon or sulfur atoms in theheterocyclyl radical may be optionally oxidized; the nitrogen atom maybe optionally quaternized; and the heterocyclyl radical may be partiallyor fully saturated. Examples of such heterocyclyl radicals may include,but are not limited to, dioxolanyl, thienyl[1,3]dithianyl,decahydroisoquinolyl, imidazolinyl, imidazolidinyl, isothiazolidinyl,isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl,2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, oxazolidinyl,piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl, pyrazolidinyl,quinuclidinyl, thiazolidinyl, tetrahydrofuryl, trithianyl,tetrahydropyranyl, thiomorpholinyl, thiamorpholinyl,1-oxo-thiomorpholinyl, and 1,1-dioxo-thiomorpholinyl. Unless statedotherwise specifically in the specification, a heterocyclyl group may beoptionally substituted.

“Heterocyclyloxy” refers to a radical of the formula —OR^(d), whereinR^(d) is a C₁-C₁₂ heterocyclyl radical as defined above. Unless statedotherwise specifically in the specification, a heterocyclyloxy group maybe optionally substituted.

“Heterocyclylalkyloxy” refers to a radical of the formula —OR^(b)R^(d)where R^(b) is a C₂-C₃₀ alkylene chain as defined above, and R^(d) is aC₁-C₁₂ heterocyclyl radical as defined above. Unless stated otherwisespecifically in the specification, a heterocyclylalkyloxy group may beoptionally substituted.

“Heterocyclylaminyl” refers to a radical of the formula —N(R^(a))₂R^(d)where R^(a) is independently H or a C₁-C₃₀ alkyl radical as definedabove, and R^(d) is a C₁-C₁₂ heterocyclyl radical as defined above.Unless stated otherwise specifically in the specification, aheterocyclylaminyl group may be optionally substituted.

“Heterocyclylalkylaminyl” refers to a radical of the formula—NR^(a)R^(b)—R^(d) where R^(a) is H or a C₁-C₃₀ alkyl radical as definedabove, R^(b) is a C₂-C₃₀ alkylene radical as defined above, and R^(d) isa C₁-C₁₂ heterocyclyl radical as defined above. Unless stated otherwisespecifically in the specification, a cycloalkylalkylaminyl group may beoptionally substituted.

“Heterocyclylcarbonyl” refers to a radical of the formula —C(═O)R^(d)where R^(d) is a C₁-C₁₂ heterocyclyl radical as defined above. Unlessstated otherwise specifically in the specification, aheterocyclycarbonyl group may be optionally substituted.

“Heterocyclylalkyl” refers to a radical of the formula —R^(b)R^(d) whereR^(b) is a C₂-C₃₀ alkylene chain as defined above, and R^(d) is a C₁-C₁₂heterocyclyl radical as defined above. Unless stated otherwisespecifically in the specification, a heterocyclylalkyl group may beoptionally substituted.

“Heteroaryl” refers to a 5 to 14 membered ring system radical comprisinghydrogen atoms, 1 to 13 carbon atoms, 1 to 6 heteroatoms selected fromthe group consisting of nitrogen, oxygen and sulfur, and at least onearomatic ring. For purposes of this invention, the heteroaryl radicalmay be a monocyclic, bicyclic, tricyclic or tetracyclic ring system,which may include fused or bridged ring systems; and the nitrogen,carbon or sulfur atoms in the heteroaryl radical may be optionallyoxidized; the nitrogen atom may be optionally quaternized. Examplesinclude, but are not limited to, azepinyl, acridinyl, benzimidazolyl,benzothiazolyl, benzindolyl, benzodioxolyl, benzofuranyl, benzooxazolyl,benzothiazolyl, benzothiadiazolyl, benzo[b][1,4]dioxepinyl,1,4-benzodioxanyl, benzonaphthofuranyl, benzoxazolyl, benzodioxolyl,benzodioxinyl, benzopyranyl, benzopyranonyl, benzofuranyl,benzofuranonyl, benzothienyl (benzothiophenyl), benzotriazolyl,benzo[4,6]imidazo[1,2-a]pyridinyl, carbazolyl, cinnolinyl,dibenzofuranyl, dibenzothiophenyl, furanyl, furanonyl, isothiazolyl,imidazolyl, indazolyl, indolyl, indazolyl, isoindolyl, indolinyl,isoindolinyl, isoquinolyl, indolizinyl, isoxazolyl, naphthyridinyl,oxadiazolyl, 2-oxoazepinyl, oxazolyl, oxiranyl, 1-oxidopyridinyl,1-oxidopyrimidinyl, 1-oxidopyrazinyl, 1-oxidopyridazinyl,1-phenyl-1H-pyrrolyl, phenazinyl, phenothiazinyl, phenoxazinyl,phthalazinyl, pteridinyl, purinyl, pyrrolyl, pyrazolyl, pyridinyl,pyrazinyl, pyrimidinyl, pyridazinyl, quinazolinyl, quinoxalinyl,quinolinyl, quinuclidinyl, isoquinolinyl, tetrahydroquinolinyl,thiazolyl, thiadiazolyl, triazolyl, tetrazolyl, triazinyl, andthiophenyl (i.e. thienyl). Unless stated otherwise specifically in thespecification, a heteroaryl group may be optionally substituted.

“Heteroarylalkyl” refers to a radical of the formula —R^(b)R^(e) whereR^(b) is a C₂-C₃₀ alkylene chain as defined above, and R^(e) is a C₁-C₁₃heteroaryl radical as defined above. Unless stated otherwisespecifically in the specification, a heteroarylalkyl group may beoptionally substituted.

The term “substituted” used herein means any of the above groups (e.g.,alkyl, alkylene, alkylcarbonyl, alkoxy, alkoxyalkyl, haloalkoxyalkyl,alkoxycarbonyl, alkoxycarbonylalkyl, aminylcarbonyl, aminylalkyl,alkylaminyl, alkyl sulfonyl, alkylsulfonylalkyl, cyanoalkyl,hydroxylalkyl, aryl, cycloalkyl, cycloalkylalkyl, cycloalkyloxy,cycloalkylaminyl, cycloalkylalkylaminyl, cycloalkylalkyloxy, haloalkyl,heterocyclyl, heterocyclyloxy, heterocyclylalkyloxy, heterocyclylaminyl,heterocyclylalkylaminyl, heterocyclylcarbonyl, heterocyclylalkyl,heteroaryl and/or heteroarylalkyl) wherein at least one hydrogen atom isreplaced by a bond to a non-hydrogen atoms such as, but not limited to:a halogen atom such as F, Cl, Br, and I; an oxygen atom in groups suchas hydroxyl groups, alkoxy groups, and ester groups; a sulfur atom ingroups such as thiol groups, thioalkyl groups, sulfone groups, sulfonylgroups, and sulfoxide groups; a nitrogen atom in groups such as amines,amides, alkylamines, dialkylamines, arylamines, alkylarylamines,diarylamines, N-oxides, imides, and enamines; a silicon atom in groupssuch as trialkylsilyl groups, dialkylarylsilyl groups, alkyldiarylsilylgroups, and triarylsilyl groups; and other heteroatoms in various othergroups. “Substituted” also means any of the above groups in which one ormore hydrogen atoms are replaced by a higher-order bond (e.g., a double-or triple-bond) to a heteroatom such as oxygen in oxo, carbonyl,carboxyl, and ester groups; and nitrogen in groups such as imines,oximes, hydrazones, and nitriles. For example, “substituted” includesany of the above groups in which one or more hydrogen atoms are replacedwith —NR^(g)R^(h), —NR^(g)C(═O)R^(h), —NR^(g)C(═O)NR^(g)R^(h),—NR^(g)C(═O)OR^(h), —NR^(g)SO₂R^(h), —OC(═O)NR^(g)R^(h), —OR^(g),—SR^(g), —SOR^(g), —SO₂R^(g), —OSO₂R^(g), —SO₂OR^(g), ═NSO₂R^(g), and—SO₂NR^(g)R^(h). “Substituted also means any of the above groups inwhich one or more hydrogen atoms are replaced with —C(═O)R^(g),—C(═O)OR^(g), —C(═O)NR^(g)R^(h), —CH₂SO₂R^(g), —CH₂SO₂NR^(g)R^(h). Inthe foregoing, R^(g) and R^(h) are the same or different andindependently hydrogen, alkyl, alkoxy, alkylaminyl, thioalkyl, aryl,aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl,N-heterocyclyl, heterocyclylalkyl, heteroaryl, N-heteroaryl and/orheteroarylalkyl. “Substituted” further means any of the above groups inwhich one or more hydrogen atoms are replaced by a bond to an amino,alkylaminyl, cyano, hydroxyl, imino, nitro, oxo, thioxo, halo, alkyl,alkoxy, alkylaminyl, thioalkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, haloalkyl, heterocyclyl, N-heterocyclyl,heterocyclylalkyl, heteroaryl, N-heteroaryl and/or heteroarylalkylgroup. In addition, each of the foregoing substituents may also beoptionally substituted with one or more of the above substituents.

“Optional” or “optionally” means that the subsequently described eventof circumstances may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances in whichit does not. For example, “optionally substituted aryl” means that thearyl radical may or may not be substituted and that the descriptionincludes both substituted aryl radicals and aryl radicals having nosubstitution.

As used herein, the term “contacting” refers to bringing two or morechemical molecules to close proximity so that a chemical reactionbetween the two or more chemical molecules can occur. For example,contacting may comprise mixing and optionally continuously mixing thechemicals. Contacting may be done by fully or partially dissolving orsuspending two or more chemicals in one or more solvents, mixing of achemical in a solvent with another chemical in solid and/or gas phase orbeing attached on a solid support, such as a resin, or mixing two ormore chemicals in gas or solid phase and/or on a solid support, that aregenerally known to those skilled in the art.

In this disclosure, we present black-to-transmissive electrochromicpolymers (hereinafter also referred to as “black polymers”) that absorbacross the entire visible spectrum and realize an obvious color changefrom black to transmissive with an applied voltage. Also provided is amethod for synthesizing a black polymer via controlling monomer feedratios in a direct arylation polymerization. The direct arylationpolymerization method features formations of C—C bonds betweenhalogenated arenes and simple arenes with active C—H bonds, therebycircumventing the preparation of organometallic derivatives anddecreasing overall production cost of conjugated polymers.

In some embodiments, provided is a black-to-transmissive electrochromicpolymer of Formula (I):

-   -   wherein    -   is of the formula

-   -   of the formula

-   -    or a combination thereof;    -   of the formula

-   -   each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ is        independently hydrogen, optionally substituted C₁-C₃₀ alkyl,        optionally substituted C₂-C₃₀ alkenyl, optionally substituted        C₂-C₃₀ alkynyl, optionally substituted C₂-C₃₀ alkylcarbonyl,        optionally substituted C₁-C₃₀ alkoxy, optionally substituted        C₃-C₃₀ alkoxyalkyl, optionally substituted C₂-C₃₀        alkoxycarbonyl, optionally substituted C₄-C₃₀        alkoxycarbonylalkyl, optionally substituted C₁-C₃₀        aminylcarbonyl, optionally substituted C₄-C₃₀ aminylalkyl,        optionally substituted C₁-C₃₀ alkylaminyl, optionally        substituted C₁-C₃₀ alkyl sulfonyl, optionally substituted C₃-C₃₀        alkylsulfonylalkyl, optionally substituted C₆-C₁₈ aryl,        optionally substituted C₃-C₁₅ cycloalkyl, optionally substituted        C₃-C₃₀ cycloalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkyl, optionally substituted C₅-C₃₀        cycloalkylalkyloxy, optionally substituted C₁-C₁₂ heterocyclyl,        optionally substituted C₁-C₁₂ heterocyclyloxy, optionally        substituted C₃-C₃₀ heterocyclylalkyloxy, optionally substituted        C₁-C₃₀ heterocyclylalkyloxy, optionally substituted C₁-C₃₀        heterocyclylaminyl, optionally substituted C₅-C₃₀        heterocyclylalkylaminyl, optionally substituted C₂-C₁₂        heterocyclylcarbonyl, optionally substituted C₃-C₃₀        heterocyclylalkyl, optionally substituted C₁-C₁₃ heteroaryl, or        optionally substituted C₃-C₃₀ heteroarylalkyl;    -   each r, s and t is independently an integer of equal to or        greater than 1;    -   n is an integer of equal to or greater than 1;

represents connection to the rest of the molecule; and

-   -   the average ratio of        ,        , and        in the polymer is x:y:z, wherein x ranges from about 0.2 to        about 0.6, y ranges from about 1.2 to about 1.45, and z ranges        from about 0.2 to about 0.45, and x+y+z is about 2.

In some embodiments, x ranges from about 0.2 to about 0.6, y ranges fromabout 1.2 to about 1.45, and z ranges from about 0.2 to about 0.35. Insome embodiments, x ranges from about 0.2 to about 0.4, y ranges fromabout 1.3 to about 1.45, and z ranges from about 0.2 to about 0.35. Insome embodiments, x is about 0.2, y is about 1.2, and z is about 0.35.In some embodiments, x is about 0.3, y is about 1.45, and z is about0.25. In some embodiments, x is about 0.4, y is about 1.35, and z isabout 0.25. In some embodiments, x is about 0.4, y is about 1.4, and zis about 0.2. In some embodiments, x is about 0.6, y is about 1.2, and zis about 0.2.

In some embodiments, each R¹ and R² is independently C₁-C₃₀ alkoxyalkyl.In some embodiments, each R¹ and R² is independently unsubstitutedC₁-C₃₀ alkoxyalkyl.

In some embodiments, each R¹ and R² is

In some embodiments, one or two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ areindependently C₁-C₃₀ alkoxy, and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸are hydrogen.

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ isindependently C₁-C₃₀ alkoxy.

In some embodiments, two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are

and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen.

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ is

In some embodiments, each R⁹ and R¹⁰ is hydrogen.

In some embodiments,

is of the formula

In some embodiments,

is of the formula

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ isindependently C₁-C₃₀ alkoxy.

In some embodiments,

is of the formula

In some embodiments,

is of the formula

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ isindependently C₁-C₃₀ alkoxy. In some embodiments, each R³ and R⁶ ishydrogen, and each R⁴ and R⁵ is

In some embodiments,

is of the formula

In some embodiments, R³ is hydrogen. In some embodiments, R³ isindependently C₁-C₃₀ alkoxy. In some embodiments, R³ is

In some embodiments,

is of the formula

In some embodiments, each R³ and R⁴ is independently hydrogen or C₁-C₃₀alkoxy. In some embodiments, each R³ and R⁴ is hydrogen or

In some embodiments,

is of the formula

In some embodiments, two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independentlyC₁-C₃₀ alkoxy, and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen.In some embodiments, two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently

and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen.

In some embodiments,

is of the formula

In some embodiments, provided is a method for synthesizing ablack-to-transmissive electrochromic polymer, comprising:

-   -   contacting Monomer 1, Monomer 2, Monomer 3 and Monomer 4 under        polymerization conditions to form the black-to-transmissive        electrochromic polymer,    -   wherein a ratio of Monomer1:Monomer2:Monomer3:Monomer4 is        1:x:y′:z, x+y′+z is about 1, x ranges from about 0.2 to about        0.6, y′ ranges from about 0.2 to about 0.45, and z ranges from        about 0.2 to about 0.45;

Monomer 1 is of the formula

Monomer 2 is of the formula

or a combination thereof,

Monomer 3 is of the formula

and Monomer 4 is of the formula

and

-   -   wherein each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ is        independently hydrogen, optionally substituted C₁-C₃₀ alkyl,        optionally substituted C₂-C₃₀ alkenyl, optionally substituted        C₂-C₃₀ alkynyl, optionally substituted C₂-C₃₀ alkylcarbonyl,        optionally substituted C₁-C₃₀ alkoxy, optionally substituted        C₃-C₃₀ alkoxyalkyl, optionally substituted C₂-C₃₀        alkoxycarbonyl, optionally substituted C₄-C₃₀        alkoxycarbonylalkyl, optionally substituted C₁-C₃₀        aminylcarbonyl, optionally substituted C₄-C₃₀ aminylalkyl,        optionally substituted C₁-C₃₀ alkylaminyl, optionally        substituted C₁-C₃₀ alkyl sulfonyl, optionally substituted C₃-C₃₀        alkylsulfonylalkyl, optionally substituted C₆-C₁₈ aryl,        optionally substituted C₃-C₁₅ cycloalkyl, optionally substituted        C₃-C₃₀ cycloalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkylaminyl, optionally substituted C₅-C₃₀        cycloalkylalkyl, optionally substituted C₅-C₃₀        cycloalkylalkyloxy, optionally substituted C₁-C₁₂ heterocyclyl,        optionally substituted C₁-C₁₂ heterocyclyloxy, optionally        substituted C₃-C₃₀ heterocyclylalkyloxy, optionally substituted        C₁-C₃₀ heterocyclylalkyloxy, optionally substituted C₁-C₃₀        heterocyclylaminyl, optionally substituted C₅-C₃₀        heterocyclylalkylaminyl, optionally substituted C₂-C₁₂        heterocyclylcarbonyl, optionally substituted C₃-C₃₀        heterocyclylalkyl, optionally substituted C₁-C₁₃ heteroaryl, or        optionally substituted C₃-C₃₀ heteroarylalkyl.

In some embodiments, x ranges from about 0.2 to about 0.6, y′ rangesfrom about 0.2 to about 0.45, and z ranges from about 0.2 to about 0.35.In some embodiments, x ranges from about 0.2 to about 0.4, y′ rangesfrom about 0.3 to about 0.45, and z ranges from about 0.2 to about 0.35.In some embodiments, x is about 0.2, y′ is about 0.2, and z is about0.35. In some embodiments, x is about 0.3, y′ is about 0.45, and z isabout 0.25. In some embodiments, x is about 0.4, y′ is about 0.35, and zis about 0.25. In some embodiments, x is about 0.4, y′ is about 0.4, andz is about 0.2. In some embodiments, x is about 0.6, y′ is about 0.2,and z is about 0.2.

In some embodiments, Monomer 1 is of the formula

In some embodiments, Monomer 2 is of the formula

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ isindependently C₁-C₃₀ alkoxy.

In some embodiments, Monomer 2 is of the formula

In some embodiments, Monomer 2 is of the formula

In some embodiments, each R³ and R⁶ is hydrogen, and each R⁴ and R⁵ isindependently C₁-C₃₀ alkoxy. In some embodiments, each R³ and R⁶ ishydrogen, and each R⁴ and R⁵ is

In some embodiments, Monomer 2 is of the formula

In some embodiments, R³ is hydrogen. In some embodiments, R³ isindependently C₁-C₃₀ alkoxy. In some embodiments, R³ is

In some embodiments, Monomer 2 is of the formula

In some embodiments, each R³ and R⁴ is independently hydrogen or C₁-C₃₀alkoxy. In some embodiments, each R³ and R⁴ is independently hydrogen or

In some embodiments, Monomer 2 is of the formula

In some embodiments, two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independentlyC₁-C₃₀ alkoxy, and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen.In some embodiments, two of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are

and the rest of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen.

In some embodiments, Monomer 3 is of the formula

In some embodiments, Monomer 4 is of the formula

In some embodiments, the polymerization condition comprises K₂CO₃,PivOH, and Pd(OAc)₂.

In some embodiments, the polymerization condition comprises about 2-3equivalent of K₂CO₃, about 0.1-0.5 equivalent of PivOH and about0.01-0.05 equivalent of Pd(OAc)₂ with respect to 1 equivalent of Monomer1.

In some embodiments, the polymerization condition comprises about 2.6equivalent of K₂CO₃, about 0.3 equivalent of PivOH and about 0.02equivalent of Pd(OAc)₂ with respect to 1 equivalent of Monomer 1.

In some embodiments, the polymerization condition further comprises aninert atmosphere and a degassed solvent selected fromN-methyl-2-pyrrolidone, N,N-dimethylacetamide, andN,N-dimethylformamide, or a combination thereof.

In some embodiments, the polymerization condition further comprises atemperature of about 100° C. to about 200° C. or about 140° C.

In some embodiments, the polymerization condition further comprisesisolating the black-to-transmissive electrochromic polymer.

In some embodiments, isolating the black-to-transmissive electrochromicpolymer comprises

-   -   transferring the reaction mixture to a solvent of CH₃OH;    -   transferring the reaction mixture to an aqueous HCl solution;    -   filtering the reaction mixture to obtain a solid material;    -   dissolving the solid material in chloroform and washing the        solid material with an aqueous HCl solution;    -   concentrating and precipitating the solid material with CH₃OH;        and    -   obtaining the polymer by filtering and drying.

In some embodiments, provided is a black-to-transmissive electrochromicpolymer synthesized by a method described herein.

In some embodiments, provided is a black-to-transmissive electrochromicpolymer, wherein the polymer is synthesized by a method comprising

-   -   contacting Monomer 1, Monomer 2, Monomer 3 and Monomer 4 under a        direct arylation polymerization condition,    -   wherein a ratio of Monomer1:Monomer2:Monomer3:Monomer4 is        1:x:y′:z, x+y′+z is about 1, x ranges from about 0.2 to about        0.6, y′ ranges from about 0.2 to about 0.45, and z ranges from        about 0.2 to about 0.45, and Monomer 1, Monomer 2, Monomer 3 and        Monomer 4 are as described herein.

In some embodiments, the ratio of Monomer1:Monomer2:Monomer3:Monomer4 is1:x:y′:z, x+y′+z is about 1, x ranges from about 0.2 to about 0.6, y′ranges from about 0.2 to about 0.45, and z ranges from about 0.2 toabout 0.35.

In some embodiments, Monomer 1 is of the formula

In some embodiments, Monomer 2 is of the formula

In some embodiments, Monomer 3 is of the formula

In some embodiments, Monomer 4 is of the formula

In some embodiments, the polymer is a black-to-transmissiveelectrochromic conjugated copolymer.

In some embodiments, the polymer has an average molecular weight ofabout 5.0-100 kDa,

In some embodiments, the polymer has a polydispersity index of about1.2-1.7.

In some embodiments, the polymer has a low band gap of about 1.61-1.65eV.

In some embodiments, the black-to-transmissive electrochromic polymerhas a normalized absorbance from about 420 nm to about 680 nm of atleast 0.7.

In some embodiments, the black-to-transmissive electrochromic polymerhas a normalized absorbance from about 420 nm to about 680 nm of atleast 0.9.

In some embodiments, x is about 0.3-0.4. In some embodiments, y′ isabout 0.35-0.45. In some embodiments, z is about 0.2-0.25.

In some embodiments, x is about 0.3, y′ is about 0.45 and z is about0.25.

In some embodiments, x is about 0.4, y′ is about 0.35 and z is about0.25.

In some embodiments, x is about 0.4, y′ is about 0.4 and z is about0.25.

In some embodiments, x is about 0.4, y′ is about 0.4 and z is about 0.2.

In some embodiments, the polymer has an absorbance spectrum during400-750 nm related to a π-π* transition.

In some embodiments, provided is a black-to-transmissive electrochromicpolymer thin film, comprising an indium tin oxide (ITO) coated glassspin-coated with a black-to-transmissive polymer described herein.

In some embodiments, the film changes color from black (L* is 0-60, a*is −10 to 5, and b* is −10 to 5) to transmissive (L* is 70 to 100, a* is−10 to 5, and b* is −10 to 5) with an applied voltage of 0-1.2 V, L*represents lightness, and a* and b* are hue and chroma values,respectively.

In some embodiments, the film changes color from black (L* is 20-50, a*is −10 to 5, and b* is −10 to 5) to transmissive (L* is 80 to 90, a* is−10 to 5, and b* is −10 to 5) with an applied voltage of 0-1.2 V, L*represents lightness, and a* and b* are hue and chroma values,respectively.

In some embodiments, the film changes color from black (L* is about49.2, a* is −10 to 5, and b* is −10 to 5) to transmissive (L* is about85, a* is −10 to 5, and b* is −10 to 5) with an applied voltage of 0-1.2V, L* represents lightness, and a* and b* are hue and chroma values,respectively.

In some embodiments, the film changes color from black (L* is 20-50, a*is −5 to 0, and b* is −10 to 0) to transmissive (L* is 80 to 90, a* is−5 to 0, and b* is −5 to 0) with an applied voltage of 0-1.2 V, L*represents lightness, and a* and b* are hue and chroma values,respectively.

In some embodiments, the film changes color from black (L* is about49.2, a* is −5 to 0, and b* is −10 to 0) to transmissive (L* is about85, a* is −5 to 0, and b* is −5 to 0) with an applied voltage of 0-1.2V, L* represents lightness, and a* and b* are hue and chroma values,respectively.

In some embodiments, the film changes color from black (L* is about49.2, a* is about 3.6, b* is about −7.7) to transmissive (L* is about85, a* is about −4.6, b* is about −5.8) with an applied voltage of about0 to about 1.2 V, L* represents lightness, and a* and b* are hue andchroma values, respectively.

In some embodiments, the film changes color from black (L*=49.2, a*=3.6,b*=−7.7) to transmissive (L*=85, a*=−4.6, b*=−5.8) with an appliedvoltage of 0-1.2 V, L* represents lightness, and a* and b* are hue andchroma values, respectively.

In some embodiments, the film reaches an optical contrast of about 70%within 10 seconds on a small conductive substrate.

In some embodiments, the film has a coloration efficiency of at least100 cm² C⁻¹, at least 125 cm² C⁻¹, at least 150 cm² C⁻¹, at least 175cm² C⁻¹, or at least 200 cm² C⁻¹.

In some embodiments, the film has a coloration time of no more than 5seconds and a bleaching time of no more than about 5 seconds.

In some embodiments, the film has a coloration time of about 3.73seconds and a bleaching time of about 3.70 seconds on small conductivesubstrate, such as a conductive substrate having an area of less than 1square inch.

In some embodiments, the film has a coloration efficiency of at least100 cm²/C.

In some embodiments, the film has an optical loss of no more than 10% orno more than 5% after 1400 long-term oxidation-reduction switch cycles.

In some embodiments, provided is an electrochromic device, comprising:

-   -   an octadecyltrichlorosilane (OTS) modified indium tin oxide        (ITO) electrode spin-coated with a black-to-transmissive        electrochromic polymer described herein as a working electrode;        and    -   a colorless ITO as a counter electrode layer.

In some embodiments, the electrochromic device displays a contrast ofabout 40% or more.

In some embodiments, the electrochromic device switches color from black(a* is −5 to 0, b* is −10 to 0) when a potential of −1V is applied totransmissive (a* is −8 to 0, b* is −5 to 0) when a potential of 1.8 V isapplied, and a* and b* are hue and chroma values, respectively. Duringthe transition of such color change, a*, b* consistently in a range of−13 to 0.

In some embodiments, the electrochromic device switches color from black(as described herein, e.g., L*=37.8, a*=2.5, b*=−6.4) when a potentialof −1 V is applied to transmissive (as described herein, e.g., L*=72.6,a*=−8.0, b*=−6.5) when a potential of 1.8 V is applied. Here, L*represents lightness (ranging from 0 to 100).

In some embodiments, the black polymer is a black-to-transmissiveelectrochromic conjugated copolymer, which absorbs across the entirevisible spectrum and realizes an obvious color change from black (asdescribed herein, e.g., L*=49.2, a*=3.6, b*=−7.7) to transmissive (asdescribed herein, e.g., L*=85, a*=−4.6, b*=−5.8) with an applied voltageof 0-1.2 V. An optical contrast as high as nearly 70% can be reachedwithin 10 seconds in electrochromic thin films made of the blackpolymer, which is superior to reported black-to-transmissiveelectrochromic materials. Moreover, long-term redox(oxidation-reduction) stability has been demonstrated with an opticalloss as low as 2.1% after 1400 switching cycles. In addition, ablack-to-transmissive ECD based on the as-prepared electrochromic filmscan be designed using a transparent indium tin oxide (ITO) as a counterelectrode for charge storage. The ECD displays high contrasts for 43.6%,switching from a saturated black state (L*=37.8, a*=2.5, b*=−6.4) to atransmissive state (L*=72.6, a*=−8.0, b*=−6.5). These outstandingperformances potentially make the black polymer a promisingelectrochromic material and can be incorporated into privacy glass,smart windows and other related electrochromic devices.

The D-A approach, alternating electron-rich and electron-deficientmoieties along a π-conjugated backbone, has been proved especiallyvaluable in the synthesis of dual-band and broadly absorbingchromophores with useful photovoltaic and electrochromic properties. Achromophore refers to an atom or group whose presence is responsible forthe color of a compound. An evolution of the two-band spectralabsorption can be observed on varying relative compositions ofelectron-rich and electron-deficient substituents along the π-conjugatedbackbone. In this regard, we have synthesized five black polymers P1-P5in a direct arylation polymerization by varying feed ratios ofelectron-rich to electron-deficient species along the conjugatedbackbone. For P1 to P5, average molecular weights (Mn) andpolydispersity index (PDI) are about 5.0 to 15.8 kDa and 1.2 to 1.7,respectively. Polydispersity index refers to either molecular mass ordegree of polymerization. Ratios of polymer components, electrochemicalproperties and GPC (Gel Permeation Chromatography) estimated molecularweights for P1 to P5 are listed in Table 1. Here, x, y′, z are feedratios of monomer 2, 3, and 4 with respect to monomer 1, and x+y′+z=1with 1.0 equivalent of monomer 1. Examples of chemical formulas ofmonomer 1, 2, 3 and 4 are presented in FIG. 1. λ_(onset) stands for anonset of a lower-energy optical transition; E_(HOMO) is a HOMO (highestoccupied molecular orbital) energy level of a black polymer; E_(LUMO) isa LUMO (lowest unoccupied molecular orbital) energy level of a blackpolymer; E_(ox) is an onset oxidation potential of a black polymer; Egis a band gap (Eg) of a black polymer.

TABLE 1 E_(ox) λ_(onset) (vs Eg E_(HOMO) E_(LUMO) Mn x + y′ + z = 1 x y′z (nm) Ag/Ag⁺) (eV) (eV) (eV) (g/mol) PDI P1 0.2 0.45 0.35 767 0.42 1.62−4.90 −3.28 15800 1.7 P2 0.3 0.45 0.25 769 0.37 1.61 −4.85 −3.24 121001.5 P3 0.4 0.4 0.25 760 0.42 1.63 −4.90 −3.27 5500 1.4 P4 0.4 0.4 0.2750 0.38 1.65 −4.86 −3.21 6400 1.4 P5 0.6 0.2 0.2 760 0.42 1.63 −4.90−3.27 5000 1.2

In some embodiments, by changing feed ratios of monomer 1, 2, 3 and 4,five different black polymers (P1, P2, P3, P4 and P5) can be obtainedwith different polymer components and molecular weights.

For P1

concentration: Monomer 1 (250 mg, 0.57 mmol), Monomer 2 (40 mg, 0.11mmol), Monomer 3 (153 mg, 0.26 mmol), and Monomer 4 (58 mg, 0.20 mmol);

obtained black polymer P1: mass=0.26 g, Mn=15.8 kDa, and PDI=1.7.

For P2 concentration: Monomer 1 (250 mg, 0.57 mmol), Monomer 2 (60 mg,0.17 mmol), Monomer 3 (153 mg, 0.26 mmol), and Monomer 4 (42 mg, 0.14mmol);

obtained black polymer P2: mass=0.25 g, Mn=12.1 kDa, and PDI=1.5.

For P3

concentration: Monomer 1 (400 mg, 0.91 mmol), Monomer 2 (128 mg, 0.36mmol), Monomer 3 (190 mg, 0.32 mmol), and Monomer 4 (67 mg, 0.23 mmol);

obtained black polymer P3: mass=0.36 g, Mn=5.5 kDa, and PDI=1.4.

For P4

concentration: Monomer 1 (400 mg, 0.91 mmol), Monomer 2 (128 mg, 0.36mmol), Monomer 3 (217 mg, 0.36 mmol), and Monomer 4 (53 mg, 0.18 mmol);

obtained black polymer P4: mass=0.28 g, Mn=6.4 kDa, and PDI=1.4.

For P5

concentration: Monomer 1 (300 mg, 0.68 mmol), Monomer 2 (144 mg, 0.41mmol), Monomer 3 (81.5 mg, 0.14 mmol), and Monomer 4 (40 mg, 0.14 mmol);

obtained black polymer P5: mass=0.25 g, Mn=5.0 kDa, and PDI=1.2.

FIG. 1 shows a reaction scheme for polymerizations of black polymers, inaccordance to exemplary embodiments of the present disclosure. Allreagents can be obtained from Sigma Aldrich or Acros and used withoutfurther purification unless otherwise noted. Ferrocene (Fc), andOctadecyltrichlorosilane (OTS) can be used without further purificationand kept in a desiccator. Propylene carbonate (PC, 99.5%) obtained fromSigma-Aldrich may be purified by a solvent purification system invacuum. Tetrabutylammonium hexafluorophosphate (TBAPF₆, ≥99.0%),platinum wire (99.0%) can be obtained from Sigma-Aldrich. ITO coatedglass slides (CG-501N-CUV) can be obtained from Delta Technologies,Ltd., and sequentially cleaned with deionized water, ethanol andacetone.

As shown in FIG. 1, to synthesize the black polymers, 1 equivalent ofMonomer 1 may be added to a reaction container, and followed bydifferent ratios of Monomer 2, 3, 4 to obtain a solution. Next, K₂CO₃,PivOH and Pd(OAc)₂ may also be added into the container to create amixture with the solution. Then O₂ is removed from the container by, forexample, purged with N₂, and this process may be repeated for threetimes. A degassed solvent, such as N-methyl-2-pyrrolidone,N,N-dimethylacetamide, or N,N-dimethylformamide, can be added to themixture in the container and the mixture may be heated, such as at atemperature of about 100° C. to about 200° C. or about 140° C. for aperiod of time under nitrogen to create a reaction mixture comprisingthe polymer. The hot reaction mixture may be first transferred to asolvent, such as CH₃OH, and then transferred to an aqueous acidsolution, such as 1M HCl. The reaction mixture can be filtered to obtaina solid material which may be further dissolved in an organic solvent,such as chloroform, and washed with an aqueous acid solution, such as 1MHCl solution. The organic phase may be concentrated and precipitatedwith another solvent, such as CH₃OH. The black polymer in a form of ablack solid can be obtained by filtering and drying the organic phase.

In one example, at a first step, 1.0 equivalent of3,4-propylenedioxythiophene (Prodot) monomer 1 may be added to a Schlenktube, and followed by different ratios of monomer 2, 3, 4 to obtain asolution. Next, K₂CO₃ (e.g., 2.6 eq.), PivOH (e.g., 0.3 eq.) andPd(OAc)₂ (e.g., 0.02 eq.) may also be added into the tube to create amixture with the solution. Then the tube may be kept under vacuum forabout 5 min and purged with N₂, and this process may be repeated forthree times. At a second step, degassed solvent N-methyl-2-pyrrolidone(NMP, and 1.0 g monomer 1 use 40 ml of solvent) can be added to themixture in the tube and the tube may be heated in an oil bath at 140° C.for 18 hour under nitrogen to create a reaction mixture. At a thirdstep, the hot reaction mixture may be first transferred to a solvent ofCH₃OH with a ratio of 1:1 and then transferred to 1M HCl with stir. At afourth step, the reaction mixture can be filtered to obtain a solidmaterial which may be further dissolved in chloroform and washed with 1MHCl solution. At a fifth step, an organic phase may be concentrated andprecipitate with CH₃OH. At a last step, the black polymer in a form of ablack solid, can be obtained by filtering and drying the organic phase.P1 to P5 were prepared accordingly.

In some embodiments, to fabricate ECDs with the obtained black polymers,firstly, conductive sides of cleaned ITO slides may be treated with aUV-ozone chamber for 20 mins to obtain functionalized ITOs. Then thefunctionalized ITOs may be immersed into an OTS/hexane solution (1 vol%) for 80 mins to form an OTS-modified ITO, and subsequently dried bynitrogen blowing. Solutions of the black polymers in chloroform (60mg/mL) then can be spin-coated (1500 rpm) onto OTS-modified ITOelectrodes to form thin electrochromic films. Thickness (˜250-450 nm) ofthe spin-coated films can be controlled via adjusting a concentration ofthe black polymer solution from 40-70 mg/mL.

To characterize the obtained black polymers and the ECDs, in someembodiments, ¹H and ¹³C NMR (nuclear magnetic resonance) spectra may berecorded on a Brucker ARX 400 at 293 K with deuterized chlorofrom assolvent. Size exclusive chromatography (SEC) may be performed intetrahydrofuran under room temperature with calibration curve based onpolystyrene standards. UV-vis-NIR spectra(ultraviolet-visible-Near-infrared spectra) may be measured with anAgilent Technologies Cary 6000i UV-Vis-NIR or Agilent Cary 5000UV-Vis-NIR spectrophotometer. All solution spectra may be collected inchloroform and thin film spectra from spin-coating samples on glasssubstrates.

In some embodiments, electrochemistry related studies of the polymerfilms may be carried out on BioLogic SP-150 in a traditionalthree-electrode system. A Pt wire may be used as a counter electrode, anAg/AgCl reference electrode may be calibrated with Fc/Fc⁺ (0.2 M ofFc/propylene carbonate (PC) in 0.2 M of TBAPF₆/PC), and the ITO-coatedblack polymer films may be used as working electrodes. The CyclicVoltammetry (CV) may be measured from 0-1.2V at 40 mV/s scan rate in a0.2 M TBAPF₆/PC electrolyte solution. CV is a type of potentiodynamicelectrochemical measurement, and is used to study the electrochemicalproperties of an analyte in solution. UV-vis spectra,Spectroelectrochemistry, Kinetic and Color measurement may be recordedon an Agilent Cary 500 Scan UV-vis-NIR spectrophotometer. Photographs ofthe polymer solutions and films may be illuminated with a D65 lightsource in building mode and recorded using a digital camera (Nikon D500)in a viewing booth (GTI Graphic Technology, Inc.) All photographs arepresented as received without further alteration.

FIG. 2A presents solution UV-visible absorption spectra of the blackpolymers from P1 to P5 in chloroform in accordance to exemplaryembodiments of the present disclosure. Insets in FIG. 2A show colors ofthe black polymers in solution. As shown in FIG. 2A, the five spectraall displayed broad “merging” band in the visible light region, which isdifferent from typical D-A polymer spectra with two single absorptionbands. In some embodiments, with a low proportion of monomer 2, P1demonstrates a deficient absorption at a short-wavelength absorption of458 nm and thus reveals a blue-green color. When the amount of monomer 2increases to 0.4 (i.e., P3), the absorbance area at low wavelength isrising and a difference in intensity between two peaks is diminishing.Hence, a further increase monomer 2 concentration may realize a broaderand completed absorption. As shown in FIG. 2A, with the increment of theratio of the electron-rich moiety from P1-P4 (0.2-0.4), P4 demonstratesthe most balanced and homogenous absorption spectrum, and almost coversthe entire visible region, which is superior to other reported blackpolymers. Further increasing the ratio of monomer 2 to 0.6, the curve ofP5 is uplifted around 420 nm, although it does not present entirely inthe short- and long-wavelength transitions, and P5 in solution exhibitsa dark blue color. Comparing the black polymers from P1-P5, bathochromicshift (except for P5) and hypsochromic shift is observed at short- andlong-wavelength transitions, respectively, which may be due to theincreasing ratio of electron-rich moiety. This result may make the twotransitions balance with each other and form a “merging” band.Bathochromic shift is a change of spectral band position in theabsorption, reflectance, transmittance, or emission spectrum of amolecule to a longer wavelength (lower frequency). Hypsochromic shift isa change of spectral band position in the absorption, reflectance,transmittance, or emission spectrum of a molecule to a shorterwavelength (higher frequency).

In some embodiments, the polymer solutions (60 mg mL⁻¹) may bespin-coated onto ITO slides, and the corresponding solid-state opticalabsorbance spectra are presented in FIG. 2B. Insets in FIG. 2B showcolors of the black polymers in solid states. All films demonstratedmore black colors and bathochromic shifts relative to their solutions.This may be resulted from a higher degree of order and a more planarityof the polymer chains in the solid state, which may lead to a more blackcolor.

In addition, the band gap (Eg) is an vital and indispensable factor forevaluating opto-electronic properties, the values can be calculated bythe onset of the lower-energy optical transition (λ_(onset),Eg=1240/λ_(onset)). Shown in FIG. 2B and Table 1, these five blackpolymers P1 to P5 have a low band gap from 1.61-1.65 eV.

FIG. 3A shows measurement results of cyclic voltammograms of P4 in 0.2 MTBAPF₆/PC at 40 mV/s; and FIG. 3B shows measurement results ofspectroelectrochemistry of P4, in accordance to exemplary embodiments inthe present disclosure. In some embodiments, the film of P4 may bespin-coated onto ITO-coated glass from chloroform (60 mg mL⁻¹). Anelectrochemical oxidation of the film may be carried out in 0.2 MTBAPF₆/PC solution, with Ag/AgCl as a quasi-reference electrode(calibrated against Fc/Fc⁺), and a platinum wire as the counterelectrode. The applied potential may be increased from 0 to +1.2 V vs.Ag/AgCl.

FIG. 3C shows data of lightness (L*) as a function of applied potentialfor spin-coated P4 film, with L*, a*, and b* values listed. The insetsin FIG. 3C are photographs of the films in fully neutral (left) andoxidized states (right), respectively. FIG. 3D shows data of square-wavepotential-step chronoabsorptometry of P4 spin-coated on ITO (monitoredat 500 nm, 0 to +1.2 V vs. Ag/AgCl in 0.2 M TBAPF₆/PC electrolytesolution) with a switching time for 100 s, 80 s, 60 s, 40 s, 20 s, 10 s,5 s, and 2 s.

In some embodiments, prior to other electrochemical and spectralinvestigation, a CV measurement may be first conducted to probe anddetermine a redox potential range, which may be cycled for several timesat 40 mV/s to obtain some stable and reproducible curves. FIG. 3Areveals a 16th CV cycles of the P4 film, exhibiting a full andirreversible switch between 0-1.2 V with an onset oxidation potential(E_(ox)) of 0.38 V versus an Ag/AgCl pseudoreference electrode.Subsequently, the film may be neutralized at −0.2 V for 60 s at the samecondition, and then changes of absorbance spectra from black totransmittance may be recorded under various applied voltages. FIG. 3Bdisplays the spectroelectrochemical series spectra of P4 film. In someembodiments, the film appears black in the neutral state, and shows abroad absorbance spectrum during 400-750 nm related to the π-π*transition, while as the polymer film is doped, the broad peak in thevisible region is depleted, and a polaronic and bipolaronic transitionappear successively in the near-IR (800-1200 nm) and IR region (>1200nm). After the complete oxidation (˜1.2 V), the absorption band arisebeyond 1600 nm, meanwhile, a transmittance change(ΔT=T_(bleached)−T_(colored)) may reach as high as nearly 70% at 500 nmfrom the colored to the bleached state, which may allow highlytransmissive films to the human eye.

In order to have an accurate assessment of the color characteristicchanges during the electrochemical switching, in some embodiments,colors can be measured quantitatively utilizing the CIE 1976 L*a*b*color standards, where CIE 1976 is a color space adopted by theInternational Commission on Illumination (CIE) in 1976, L* representslightness (ranging from 0 to 100), and a* and b* are hue and chromavalues, respectively. More specifically, positive and negative a* valuescorrespond to red and green hues, respectively, and positive andnegative b* values denote yellow and blue chromas. Colorimetricalmeasurements of the black polymer films have been investigated, and P4shows a relatively blacker color in comparison with others. The resultsare listed in Table 2. Here, t_(c) is a coloration time, t_(b) is ableaching time and CE is coloration efficiency.

TABLE 2 ΔT CE λ_(max) (%, at (cm² t_(b) t_(c) (nm) L a b L* a* b* 10 s)C⁻¹) (s) (s) P1 630 23.7 −20.0 −15.9 61.5 −17.8 −25.9 43.76 205.1 8.306.00 P2 626 31.0 −8.7 −10.8 75.1 −8.7 −11.7 51.56 199.6 4.61 5.04 P3 48228.6 −7.0 −9.9 68.1 −10.7 −16.7 57.03 165.7 4.89 4.60 P4 500 49.2 3.6−7.7 85.0 −4.6 −5.8 69.68 202.4 3.73 3.70 P5 630 44.0 −13.9 −11.2 76.9−7.4 −11.0 45.62 188.0 3.83 2.38

In some embodiments, colorimetrical measurements may also be performedvia varying film thickness. For example, the absorption maximum for thethree films of different thickness can be: A1=0.43 a.u., A2=0.77 a.u.,and A3=1.10 a.u. respectively, as shown in FIG. 3C. In a neutral state,the L* values of the films exhibit from 39.7 (A3=1.10 a.u.) to 67.4(A1=0.43 a.u.). When the applied potential is added up to 0.4 V, thebleaching process may occur, which is consistent with the CV results. Asthe oxidation degree increases gradually, visible absorption regions areundergoing depletion, and polaronic and bipolaronic transitions mayprogress with colors varying from colored to transmissive. Incomparison, the film with the absorption maximum of 0.77 a.u. may obtaina maximum contrast for nearly 70% from a deep black color (L*=49.2,a*=3.6, b*=−7.7) to a highly transmissive near colorless state (L*=85,a*=−4.6, b*=−5.8) upon doping.

Furthermore, coloration switching response and coloration efficiency mayalso be pivotal factors to assess electrochromic materials in practicalapplications of display and window devices. In some embodiments, thefilm switching may be first examined using transmittance change at acertain wavelength as a function of switch time by applying square-wavepotential steps for periods of 100, 80, 60, 40, 20, 10, 5, and 2 s. Asshown in FIG. 3D, FIGS. 4A-D, and Tables 2, the P4 film shows a largesttransmittance change monitored, an excellent switching performance ashigh as 69.7% at a longer switch time (100 s), also maintaining ΔT>63.2%at 5 s and above. However, the ΔT decreased to 46.0% (a 23.72% loss) ata faster switching pulse of 2 s. Table 3 shows the ΔT of FIGS. 4A-D.

TABLE 3 ΔT (%) polymer 100 s 80 s 60 s 40 s 20 s 10 s 5 s 2s 100 s (2)P1 51.6 51.0 50.8 50.6 47.2 46.2 35.9 11.2 51.4 P2 43.8 43.1 42.3 40.033.7 26.9 14.6 4.1 43.3 P3 57.0 56.0 55.4 54.7 54.0 52.6 45.3 46.0 55.11P4 45.6 44.8 44.6 44.4 44.3 43.8 42.2 26.8 45.2

In some embodiments, an interval time of 10 s (ΔT₁₀=68.4) may be chosento investigate coloration rate and efficiency, as shown in FIGS. 5A-B.The measurements may be performed by a combination of chronoamperometryand an in-situ UV-vis-NIR spectrophotometer via alternating potentialsfrom 0 to 1.2 V. Herein, a response time may be defined as the timerequired for a 90% change in the full transmittance at 500 nm. In someembodiments, an as-prepared P4 film, the coloration time (t_(c)) may be3.73 s, and the bleaching time (ti) may be 3.7 s. The fast switchingspeed may be due to a good connection between an active film (P4) andthe OTS-functionalized ITO substrate.

A coloration efficiency (CE, η) is defined as the change in opticaldensity (OD) per unit of inserted charge (Q), which are measured in asimultaneous chronocoulometry and chronoabsorptometry experiment, withthe percent transmittance during the switch monitored at the absorbancemaxima. Chronocoulometry is used to study kinetics of chemicalreactions, diffusion processes, and adsorption. In this technique, apotential step is applied to an electrode and the resulting cumulativecharge vs. time is observed. This technique is very similar toChronoamperometry, except that the integrated charge is recorded inChronocoulometry instead of raw current. The coloration efficiency canbe calculated via η=ΔOD/ΔQ. In some embodiments, a CE value of 202.4 cm²C⁻¹ may be obtained for the P4 film (shown in Table 2 and FIG. 5B),which is superior and comparable to those of previously reported blackpolymer materials.

In addition, stability is another crucial parameter in a practicalutilization of electrochromic materials. In some embodiments, thestability of repeated redox test may be carried out by repeatingsquare-wave potential steps of 10 s (switching between 0 to 1.2 V vs.Ag/AgCl) for 1400 cycles. As shown in FIG. 3D, the film demonstratedoutstanding switching stability with only a decrease of 2.1% fortransmittance changes.

In some embodiments, to verify utility of the black polymers,black-to-transmissive ECDs may be assembled with P4 as a workingelectrode and a colorless ITO as a counter electrode layer,respectively. Transmittance spectra of the ECDs in the neutral andbleaching state may be measured across the entire visible region, andthe detail changes may be shown in FIG. 6. Insets in FIG. 6 showphotographs of a same device in reduction and oxidation states. In someembodiments, a potential of 1.8 V is applied to a device, and the devicemay become highly transmissive (e.g., L*=72.6, a*=−8, b*=−6.5). When thepotential is decreased to −1.0 V, the device may recover to its blackstate (e.g., L*=37.8, a*=2.5, b*=−6.4) with a transmittance contrast ofabout 43.6% at 500 nm. Hence, polymer P4 can be validated to be aneffective and valuable electrochromic material. Further efforts may beput into searching for a well-matched courter electrode and constructinga high-performance ECD.

Based on measurement results, we find that through governing thevariation of the merging band with various compositions, ablack-to-transmissive electrochromic material with relatively homogenousand broad absorption band can be synthesized. With 1 equivalent ofMonomer 1, the feed ratios of Monomers 2, 3 and 4 may range from0.2-0.6, 0.2-0.45, 0.2-0.35, respectively. The synthesized blackmaterial can be realized a tunable color switching from saturated blackto transmissive, which are superior to previous reportedblack-to-transmissive electrochromic materials.

In this disclosure, a method for synthesizing black-to-transmissiveelectrochromic polymers is disclosed. Black polymers may be developedvia controlling a monomer feed ratio in a direct arylationpolymerization. Spectroelectrochemistry and colorimetry may exhibit aclear black-to-transmissive upon electrochemical doping. An optimalelectrochromic polymer demonstrated high-performance in terms of mostbroad and uniform visible absorption, a high optical contrast, andlong-term redox stability. Hence, this disclosure presents a strategy todesign and synthesis electrochromic materials. The high-performanceresulting black-to-transmissive polymers can be exploited in privacyglass, optical communication, data storage and some relatedelectrochromic devices.

The disclosure described and claimed herein is not to be limited inscope by the specific preferred embodiments disclosed herein, as theseembodiments are intended as illustrations of several aspects of thedisclosure. Indeed, various modifications of the disclosure in additionto those shown and described herein will become apparent to thoseskilled in the art from the foregoing description. Such modificationsare also intended to fall within the scope of the appended claims.

What is claimed is:
 1. A method for synthesizing a black-to-transmissiveelectrochromic polymer, comprising: contacting Monomer 1, Monomer 2,Monomer 3 and Monomer 4 under polymerization conditions to form theblack-to-transmissive electrochromic polymer, wherein a ratio ofMonomer1:Monomer2:Monomer3:Monomer4 is 1:x:y′:z, x+y′+z is about 1, xranges from about 0.2 to about 0.6, y′ ranges from about 0.2 to about0.45, and z ranges from about 0.2 to about 0.45; Monomer 1 is of theformula

Monomer 2 is of the formula

 or a combination thereof, Monomer 3 is of the formula

and Monomer 4 is of the formula

 and wherein each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ isindependently hydrogen, optionally substituted C₁-C₃₀ alkyl, optionallysubstituted C₂-C₃₀ alkenyl, optionally substituted C₂-C₃₀ alkynyl,optionally substituted C₂-C₃₀ alkylcarbonyl, optionally substitutedC₁-C₃₀ alkoxy, optionally substituted C₃-C₃₀ alkoxyalkyl, optionallysubstituted C₂-C₃₀ alkoxycarbonyl, optionally substituted C₄-C₃₀alkoxycarbonylalkyl, optionally substituted C₁-C₃₀ aminylcarbonyl,optionally substituted C₄-C₃₀ aminylalkyl, optionally substituted C₁-C₃₀alkylaminyl, optionally substituted C₁-C₃₀ alkyl sulfonyl, optionallysubstituted C₃-C₃₀ alkylsulfonylalkyl, optionally substituted C₆-C₁₈aryl, optionally substituted C₃-C₁₅ cycloalkyl, optionally substitutedC₃-C₃₀ cycloalkylaminyl, optionally substituted C₅-C₃₀cycloalkylalkylaminyl, optionally substituted C₅-C₃₀ cycloalkylalkyl,optionally substituted C₅-C₃₀ cycloalkylalkyloxy, optionally substitutedC₁-C₁₂ heterocyclyl, optionally substituted C₁-C₁₂ heterocyclyloxy,optionally substituted C₃-C₃₀ heterocyclylalkyloxy, optionallysubstituted C₁-C₃₀ heterocyclylalkyloxy, optionally substituted C₁-C₃₀heterocyclylaminyl, optionally substituted C₅-C₃₀heterocyclylalkylaminyl, optionally substituted C₂-C₁₂heterocyclylcarbonyl, optionally substituted C₃-C₃₀ heterocyclylalkyl,optionally substituted C₁-C₁₃ heteroaryl, or optionally substitutedC₃-C₃₀ heteroarylalkyl.
 2. The method of claim 1, wherein Monomer 1 isof the formula


3. The method of claim 1, wherein Monomer 2 is of the formula


4. The method of claim 1, wherein Monomer 3 is of the formula


5. The method of claim 1, wherein Monomer 4 is of the formula


6. The method of claim 1, wherein the polymerization condition comprisesK₂CO₃, PivOH, and Pd(OAc)₂.
 7. The method of claim 1, whereinpolymerization condition comprises about 2-3 equivalent of K₂CO₃, about0.1-0.5 equivalent of PivOH and about 0.01-0.05 equivalent of Pd(OAc)₂with respect to 1 equivalent of Monomer
 1. 8. The method of claim 1,wherein polymerization condition comprises about 2.6 equivalent ofK₂CO₃, about 0.3 equivalent of PivOH and about 0.02 equivalent ofPd(OAc)₂ with respect to 1 equivalent of Monomer
 1. 9. The method ofclaim 1, wherein the polymerization condition further comprises an inertatmosphere and a degassed solvent selected from N-methyl-2-pyrrolidone,N,N-dimethylacetamide, and N,N-dimethylformamide, or a combinationthereof.
 10. The method of claim 1, wherein the polymerization conditionfurther comprises a temperature of about 100° C. to about 200° C. orabout 140° C.
 11. The method of claim 1, further comprising isolatingthe black-to-transmissive electrochromic polymer.
 12. The method ofclaim 11, wherein isolating the black-to-transmissive electrochromicpolymer comprises transferring the reaction mixture to a solvent ofCH₃OH; transferring the reaction mixture to an aqueous HCl solution;filtering the reaction mixture to obtain a solid material; dissolvingthe solid material in chloroform and washing the solid material with anaqueous HCl solution; concentrating and precipitating the solid materialwith CH₃OH; and obtaining the polymer by filtering and drying.
 13. Ablack-to-transmissive electrochromic polymer of Formula (I):

wherein

is

 or a combination thereof;

is

 or a combination thereof;

is

each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ is independentlyhydrogen, optionally substituted C₁-C₃₀ alkyl, optionally substitutedC₂-C₃₀ alkenyl, optionally substituted C₂-C₃₀ alkynyl, optionallysubstituted C₂-C₃₀ alkylcarbonyl, optionally substituted C₁-C₃₀ alkoxy,optionally substituted C₃-C₃₀ alkoxyalkyl, optionally substituted C₂-C₃₀alkoxycarbonyl, optionally substituted C₄-C₃₀ alkoxycarbonylalkyl,optionally substituted C₁-C₃₀ aminylcarbonyl, optionally substitutedC₄-C₃₀ aminylalkyl, optionally substituted C₁-C₃₀ alkylaminyl,optionally substituted C₁-C₃₀ alkyl sulfonyl, optionally substitutedC₃-C₃₀ alkylsulfonylalkyl, optionally substituted C₆-C₁₈ aryl,optionally substituted C₃-C₁₅ cycl ° alkyl, optionally substitutedC₃-C₃₀ cycloalkylaminyl, optionally substituted C₅-C₃₀cycloalkylalkylaminyl, optionally substituted C₅-C₃₀ cycloalkylalkyl,optionally substituted C₅-C₃₀ cycloalkylalkyloxy, optionally substitutedC₁-C₁₂ heterocyclyl, optionally substituted C₁-C₁₂ heterocyclyloxy,optionally substituted C₃-C₃₀ heterocyclylalkyloxy, optionallysubstituted C₁-C₃₀ heterocyclylalkyloxy, optionally substituted C₁-C₃₀heterocyclylaminyl, optionally substituted C₅-C₃₀heterocyclylalkylaminyl, optionally substituted C₂-C₁₂heterocyclylcarbonyl, optionally substituted C₃-C₃₀ heterocyclylalkyl,optionally substituted C₁-C₁₃ heteroaryl, or optionally substitutedC₃-C₃₀ heteroarylalkyl; each r, s and t is independently an integer ofequal to or greater than 1; n is an integer of equal to or greater than1;

represents connection to the rest of the molecule; and the average ratioof

,

and

in the polymer is x:y:z, wherein x ranges from about 0.2 to about 0.6, yranges from about 1.2 to about 1.45, and z ranges from about 0.2 toabout 0.45, and x+y+z is about
 2. 14. The polymer of claim 13, whereineach R¹ and R² is independently C₁-C₃₀ alkoxyalkyl.
 15. The polymer ofclaim 13, wherein each R¹ and R² is


16. The polymer of claim 13, wherein each R³ and R⁶ is hydrogen, andeach R⁴ and R⁵ is independently C₁-C₃₀ alkoxy.
 17. The polymer of claim13, wherein each R³ and R⁶ is hydrogen, and each R⁵ and R⁵ is


18. The polymer of claim 13, wherein each R⁹ and R¹⁰ is hydrogen.
 19. Ablack-to-transmissive electrochromic polymer thin film, comprising anindium tin oxide (ITO) coated with a black-to-transmissive polymer ofclaim
 13. 20. An electrochromic device, comprising: anoctadecyltrichlorosilane (OTS) modified indium tin oxide (ITO) electrodespin-coated with a black-to-transmissive electrochromic polymer of claim13; and a colorless ITO as a counter electrode layer.